地黄连作障碍机制分析

本研究采用土壤微生物平板分离技术和16S rRNA基因序列分析技术，旨在研究化感细菌与地黄生长的关系，阐明引起地黄连作障碍的原因。从地黄连作1年的土壤中分离到19株细菌，其中2株细菌为恶臭假单胞菌(Pseudomonas putida DH03)和河生肠杆菌(Enterobacter amnigenus DH05)；DH03菌株和DH05菌株不侵染地黄叶片，但其代谢产物对地黄叶片及块根有毒害作用，为典型的化感细菌；而地黄块成分对DH03菌株和DH05菌株的生长有促进作用。根据化感细菌与地黄的相互作用，提出了引起地黄连作障碍的化感细菌作用假说，化感细菌的化感作用是引起地黄连作障碍的重要原因之一。

Mechanism Analysis of Rehmannia glutinosa Continue Cropping Problems

This study aimed to study the relationship between allelopathic bacteria and Rehmannia glutinosa growth,and clarify the causes of R.glutinosa continuous cropping cbstacle by using soil microbial plate isolation technique and 16S rRNA gene analysis method.From 1 year R.glutinosa replanted soil,19 strains of bacteria were extracted,two of which were identified to be Pseudomonas putida DH03 and Enterobacter amnigenus DH05.Strain DH03 and strain DH05 didn ＇ t infect R.glutinosa leaves.However,their metabolites had toxic effects on both leaves and tubes of R.glutinosa,and were typical allelopathic bacteria.Meanwhile,constitutes of R.glutinosa had a positive effect on the growth of strain DH03 and strain DH05.Based on the interactive effects between allelopathic bacteria and R.glutinosa,the hypothesis was proposed on the allelopathic bacterial effect which had caused the R.glutinosa continuous cropping cbstacle.Allelopathy of allelopathic bacteria was one of the main factors that had caused R.glutinosa continuous cropping obstacle.